Most policies in place require about one foot of vent area for every one hundred fifty feet of attic space.
Roof turbine vent installation height.
Also this will give you general guidelines to follow as you complete your project.
If you are going to install multiple vents you need to divide the lengths that you have measured by the number of turbines that you are going to install.
Attic must have 5 sq.
Roof cutout decide where to place turbines then from inside the attic drill a hole 18 to 30 down from the roof peak and midway between the rafters put a stick up through the hole to locate it from outside go back on the roof and mark a hole 12 in diameter for a 12 turbine or 14 in.
This is one of the most important steps.
These can be ridge vents wind turbines or the flat vents your roofer wants to install.
A third vent should be between the two.
Good attic ventilation is important for preventing ice dams in the winter.
To begin you will need to measure the length and width of the sides of the roof where you are going to install the turbine.
A single 12 inch diameter turbine vent could provide a complete change of air in the attic space every 52 minutes if the outside breeze was just 5 mph.
But consider a moderately sized home whose attic space is 36 feet deep 50 feet long and 10 feet high at the peak.
The installation of a turbine vent is nearly identical to a static vent.
This attic space contains 18 000 cubic feet of air.
This is most effective in areas where winds average at least five miles per hour or otherwise will not offer the most effective reliable source of venting.
How to install turbine vents.
If you install a vent that isn t up to code you could end up having to take it down wasting money and time.